SU1722756A1 - Process for producing powder wire rod for welding and filling - Google Patents

Abstract

The invention relates to welding and can be used in the manufacture of cored wires for welding and cladding. The purpose of the invention is to increase the productivity of the manufacture of cored wire while maintaining its technological reliability. The powder wire contains a two-layer sheath, the outer layer of which is made of fast-strength and wedge material, and the inner one is made of ductile. The simultaneous compression of the contacting layers is carried out simultaneously, and the ratio of the thicknesses of the inner and outer layers is chosen in the range of 0.12-0.30. 4 ill., 1 tab.

Description

The invention relates to welding in petrochemical, nuclear power and general engineering and can be used in the manufacture of flux-cored wires mainly for electric arc and electroslag welding and cladding.

An external characteristic of flux-cored wire is its technological reliability, which depends on the design and method of making the wire and includes such indicators as the mechanical strength of the sheath, uniform distribution and reliable isolation of the mixture from air, and simplicity and productivity of the method of manufacture.

Production of flux-cored wires with shells of high-strength materials during deformation (nickel and its alloys, corrosion-resistant steels, etc.) is not established in the USSR because of the low processability of the process, and modern industry requires mass production of this

products. To produce cored wire (PP) with a sheath of such materials can only be annealed by successive deformation of the wire on drawing machines. This significantly reduces product quality due to oxidation of the mixture during heating. Manufactured according to the traditional technology, PP from a fast-hardening material has low technological reliability due to poor sealing of the charge, which leads to its hydration, oxidation and precipitation into the resulting gaps.

High-tech, have a good tightness and uniform distribution of the charge PP, made in the traditional way from one tape, formed into two shells.

But the shell of such wires can be made only from tapes with a thickness of no more than 0.2 mm. Otherwise, when using the most acceptable in the industry tapes with a thickness of 0.4-0.8

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mm, in particular, of high-strength materials, when materials are deformed, a shell is not formed.

Known PP, having two shells: outer and inner. The inner shell with the charge is placed in the outer, which is a tubular casing, the junction of the edges of which is sealed, thus ensuring reliable insulation of the charge.

However, the low ductility of the weld leads to insufficient technological reliability of the PP, since in the process of its manufacture (rolling, drawing), delamination and breakages are observed. Annealing of the wire is required to prevent defects, which is undesirable.

Closest to the present invention is a method of manufacturing PP, in which the wire contains at least two sheaths with process joints diametrically opposed to each other, and the charge is in the inner and between the inner and outer shells.

However, the process of making this wire is complicated and time consuming. The inner shell is filled with the charge, crimped, dragged to the required diameter, laid into the channel of the new shell, dragged again to the size of the stack, etc. After the final installation, the wire is drawn to the diameter of the finished product. In order to eliminate intermediate drawing, it is necessary to have tapes / sizes which would correspond to the dimensions of the laying of the shells.

The purpose of the invention is to increase the productivity of the process of manufacturing cored wire while maintaining its high technological reliability.

The goal is achieved by the fact that the technological joints of a two-layer shell with a mixture, the outer layer of which is made of fast-strength material during deformation, and the inner one is made of plastic, are diametrically opposed to each other and joint simultaneous compression of the contacting layers is carried out, and the outer layer is chosen in the range of 0.12-0.30.

FIG. Figure 1 shows the wire fabrication scheme; in fig. 2 is a section A-A in FIG. one; in fig. 3 is a sectional view in FIG. one; in fig. 4 shows a section B-B in FIG. one.

The device for producing wire contains a cassette 1 (Fig. 1) with a tape of the outer layer of the sheath, a cassette 2 with a tape of the inner layer, two forming devices 3, a batcher 4 of the charge, dies 5 and a drum b for winding the finished product ..

The process of making PP consists of forming a two-layer shell and one or two pastes through dies to a predetermined diameter and consists of the following.

Tape the outer and inner layers of the shell is passed through a forming device 3, giving them the shape of segments

the cylindrical surface (Fig. 2), the tape of the inner layer is then passed through the dispenser 4, which fills it with the charge (Fig. 3), after which both tapes are jointly compressed in the die 5. The contacting of the layers with each other and their various materials ensure the possibility of their joint simultaneous deformation (the outer layer is deformed mainly in the elastic region, and the inner one - in

plastic), which, after removal of the load, leads to complete closure of the internal joint, uniform compression of the charge and its sealing.

In the subsequent drawing to a given diameter, the process is similarly repeated, providing a high degree of compaction of the charge without stratification and wire breaks. The compression of the layers is such that the outer and inner joints are diametrically opposite to each other. The finished two-layer PP (Fig. 4, where 7 is the outer layer, 8 is the inner layer, 9 is the charge) is wound on the drum 6.

Example. Cored wire

made by the proposed method of the following materials: the outer layer of the shell is made of nickel tape NP2 0.5 x 15, GOST 2170-73, and the inner layer is made of steel

CB-08kp tapes (ТУ 503-71) with the following thickness ratios: 0.12; 0.30; 0.10; 0.20; 0.35. A mixture of powders of metals and minerals was used as the charge; the filling coefficient was 0.4. The iron content in the nickel deposited metal with the proposed boundary ratio of the cladding layers was not more than 15%. The limitation of the iron content in such alloys is explained by their deterioration

welding and technological properties.

The wire was obtained by forming a two-layer sheath with a cavity filled with a charge. In this case, the outer layer was made of high-strength material during deformation (nickel tape), and the inner layer was made of ductile (steel tape), the layer joints diametrically opposed to each other. Consecutive drawing through dies different.

diameters received wire with a diameter of 3 mm,

In tests of manufactured cored wires, their technological reliability and the iron content in the weld metal were evaluated. The quality criterion of the material, characterized by the tightness of the shell and the uniform distribution of the charge over the length of the wire, the mechanical strength of the shell, and the laboriousness of manufacturing were taken as the criterion of reliability.

It has been established that a two-layer PP fabricated by the proposed method with a thickness ratio of 0.12-0.30 has an increased process reliability, consisting in sufficient shell strength, good sealing of the charge and its uniform distribution along the length of the wire. During the manufacturing process, there were no breaks in the shell layers.

In the manufacture of PP with a ratio of the thickness of the shell layers beyond the proposed limits, a decrease in its technological properties and quality is observed: a decrease in the ratio from 0.12 to 0.10 leads to local breaks of the inner layer, and an increase from 0.30 to 0 , 35 causes an increased share of the participation in the fused metal, which reduces its welding and technological properties.

Research data are summarized in the table. Analysis of the data in the table shows that the proposed method of manufacturing PP exceeds those known by criteria of technological reliability.

The application of the proposed method in the industry, in comparison with the known ones, provides the following advantages: it allows to significantly expand the range of PP, the shell of which is made of fast-strength materials during deformation; reduces labor intensity and increases productivity of manufacturing two-layer and multilayer PP; reduces the production of more expensive cold and hot-rolled wires from high-strength steels for welding and surfacing; It is possible to manufacture on industrial equipment with a slight readjustment of the latter.

Fo rmu l and z o f i n A method for the manufacture of cored wire for welding and surfacing, in which the cored wire sheath is made two-layer, containing layers of materials of different composition, and the technological joints are diametrically opposed to one another, characterized in that, in order to increase the productivity of wire production while maintaining its technological reliability, the inner layer is made of ductile metal, and the outer layer is made of fast-strength metal, the ratio of their thickness n is chosen in the range of 0.12-0.30, with compression of the shells being carried out jointly.

The results of the base, known and proposed. of objects

Known 90-120 130-150 Basic 200-250 130-150

iron percentage

The manufacturing process is complex and time consuming.

Unreliable, cannot be used in industry

Aa

Bb

Bb

Claims (1)

Claim A method of manufacturing a flux-cored wire for welding and surfacing, in which the casing of the flux-cored wire is made of two layers containing layers of materials of different compositions, and technological joints are diametrically opposed to one another, characterized in that, in order to increase the productivity of manufacturing the wire while maintaining it technological reliability, the inner layer is made of 30 from ductile metal, and the outer one is made of quick-strengthening, the ratio of their thicknesses is chosen in the range of 0.12-0.30, moreover, the compression shells produce together. Results of basic, well-known and proposed objects Cooking method Productivity, kg / h The strength of the shell, MPa G ----------- The ratio of internal thickness. him and the outer layers of the shell The iron content in the weld metal,% PP technological reliability level Proposed 200 - 250 150 - 180 0.12 o, zo 0.20 6.7 14.0 10.0 Reliable, the method can be applied in industry 0.10 5/ · ' Unreliable, clippings of the inner layer of the shell 0.35 15,5 Unreliable, high percentage of iron Famous 90 - 120 130 - 150 - - The manufacturing process is complex and time-consuming. Base 200 - 250 130 - 150 Unreliable, cannot be used in industry A-A B-B V-V Chi